Premature BirthObstetric Labor, PrematurePregnancyFetal Membranes, Premature RuptureCerclage, CervicalCervical Length MeasurementGestational AgeCervix UteriUterine Cervical IncompetencePregnancy Trimester, SecondChorioamnionitisTocolytic AgentsInfant, PrematureInfant, NewbornPregnancy, High-RiskPregnancy OutcomeHistocompatibility, Maternal-FetalVaginosis, BacterialPessariesUltrasonography, PrenatalPregnancy ComplicationsVaginaPreconception CareAmniotic FluidCervical RipeningTwinsBirth WeightRisk FactorsTerm BirthParityInfant, Low Birth WeightPregnancy Trimester, FirstLogistic ModelsProspective StudiesModels, EconometricMaternal Nutritional Physiological PhenomenaVitamin B ComplexPregnancy, MultipleCohort StudiesInfant, Small for Gestational AgeCase-Control StudiesAbortion, HabitualPregnancy Trimester, ThirdPregnancy Complications, InfectiousPelvic InfectionExtraembryonic MembranesInfant, Premature, DiseasesOdds RatioUterine MonitoringPredictive Value of TestsMaternal AgeBirth RateMycoplasma hominisSensitivity and SpecificityLabor, InducedDietary SupplementsAmniocentesisRetrospective StudiesUreaplasma InfectionsPre-EclampsiaUterine ContractionUreaplasma urealyticumInfant MortalityBirth CertificatesStillbirthPlacentaInfant, Extremely PrematurePrenatal CareFetal DeathBirth OrderAfrican AmericansBirth IntervalsDelivery, ObstetricPerinatal CareRisk AssessmentROC CurveRespiratory Distress Syndrome, NewbornCesarean SectionInfant, Very Low Birth WeightMultiple Birth OffspringMaternal ExposureHydroxyprogesteronesDevelopmental DisabilitiesAdministration, IntravaginalBiological MarkersBronchopulmonary DysplasiaCongenital AbnormalitiesFetal Growth RetardationIntensive Care Units, NeonatalChild DevelopmentIntensive Care, NeonatalTocolysisCross-Sectional StudiesMothersPregnancy, TwinParturitionInfant CareLabor, ObstetricProgestinsAbortion, Spontaneous